JP7611532B2 - Quality change detection method, quality change detection system, and program - Google Patents

Description

The present disclosure generally relates to a quality change detection method, a quality change detection system, and a program.

Patent document 1 describes an installed component inspection device for inspecting the mounting state of components on a printed circuit board. The installed component inspection device described in patent document 1 detects mounting defects of components based on captured images of the mounting positions of the components on the printed circuit board.

JP 2000-349499 A

The object of the present disclosure is to provide a quality change detection method, a quality change detection system, and a program that can prevent the occurrence of defective mounting of a second object on a first object.

A quality change detection method according to one aspect of the present disclosure includes an acquisition step and a first determination step. The acquisition step is a step of acquiring a mounting position deviation amount, which is a difference between an actual mounting position of a second object relative to a first object and a target mounting position. The first determination step is a step of determining that the mounting quality has changed when the mounting position deviation amount acquired in the acquisition step exceeds a first determination range and falls within a second determination range. The first determination range is included in the second determination range in which the mounting quality is determined to be normal. The quality change detection method further includes a second determination step of determining that the mounting quality has changed based on statistical information related to the mounting position deviation amount included in the first determination range.
A quality change detection method according to another aspect of the present disclosure includes an acquisition step and a first determination step. The acquisition step is a step of acquiring a mounting position deviation amount, which is a difference between an actual mounting position of a second object relative to a first object and a target mounting position. The first determination step is a step of determining that the mounting quality has changed when the mounting position deviation amount acquired in the acquisition step exceeds a first determination range and falls within a second determination range. The first determination range is included in the second determination range in which the mounting quality is determined to be normal. The first determination range is set according to a mounting angle of the second object relative to the first object.
A quality change detection method according to another aspect of the present disclosure includes an acquisition step and a first determination step. The acquisition step is a step of acquiring a mounting position deviation amount, which is a difference between an actual mounting position of a second object relative to a first object and a target mounting position. The first determination step is a step of determining that the mounting quality has changed when the mounting position deviation amount acquired in the acquisition step exceeds a first determination range and falls within a second determination range. The first determination range is included in the second determination range in which the mounting quality is determined to be normal. The quality change detection method further includes a prediction step of predicting an abnormality in the mounting quality based on first information regarding the mounting position deviation amount.
A quality change detection method according to another aspect of the present disclosure includes an acquisition step and a first determination step. The acquisition step is a step of acquiring a mounting position deviation amount, which is a difference between an actual mounting position of a second object relative to a first object and a target mounting position. The first determination step is a step of determining that the quality of mounting has changed when the mounting position deviation amount acquired in the acquisition step exceeds a first determination range and falls within a second determination range. The first determination range is included in the second determination range in which the quality of mounting is determined to be normal. The quality change detection method further includes an estimation step of estimating a malfunction location in a mounting system that is a cause of the change in the quality of mounting, based on first information regarding the mounting position deviation amount. In the estimation step, in addition to the first information, second information is used that corresponds to the mounting position deviation amount and is related to equipment used when mounting the second object on the first object.

A quality change detection system according to an aspect of the present disclosure includes an acquisition unit and a determination unit. The acquisition unit acquires a mounting position deviation amount, which is a difference between an actual mounting position of a second object relative to a first object and a target mounting position. The determination unit determines that the mounting quality has changed when the mounting position deviation amount acquired by the acquisition unit exceeds a first determination range and falls within a second determination range. The first determination range is included in the second determination range in which the mounting quality is determined to be normal. The quality change detection system further includes a second determination unit that determines that the mounting quality has changed based on statistical information related to the mounting position deviation amount included in the first determination range.
A quality change detection system according to another aspect of the present disclosure includes an acquisition unit and a determination unit. The acquisition unit acquires a mounting position deviation amount, which is a difference between an actual mounting position of a second object relative to a first object and a target mounting position. The determination unit determines that the mounting quality has changed when the mounting position deviation amount acquired by the acquisition unit exceeds a first determination range and falls within a second determination range. The first determination range is included in the second determination range in which the mounting quality is determined to be normal. The first determination range is set according to a mounting angle of the second object relative to the first object.
A quality change detection system according to another aspect of the present disclosure includes an acquisition unit and a determination unit. The acquisition unit acquires a mounting position deviation amount, which is a difference between an actual mounting position of a second object relative to a first object and a target mounting position. The determination unit determines that the mounting quality has changed when the mounting position deviation amount acquired by the acquisition unit exceeds a first determination range and falls within a second determination range. The first determination range is included in the second determination range in which the mounting quality is determined to be normal. The quality change detection system further includes a prediction unit that predicts an abnormality in the mounting quality based on first information regarding the mounting position deviation amount.
A quality change detection system according to another aspect of the present disclosure includes an acquisition unit and a determination unit. The acquisition unit acquires a mounting position deviation amount, which is a difference between an actual mounting position of a second object relative to a first object and a target mounting position. The determination unit determines that the mounting quality has changed when the mounting position deviation amount acquired by the acquisition unit exceeds a first determination range and falls within a second determination range. The first determination range is included in the second determination range in which the mounting quality is determined to be normal. The quality change detection system further includes an estimation unit that estimates a malfunction location in a mounting system that is a factor of the change in the mounting quality based on first information related to the mounting position deviation amount. The estimation unit uses second information related to equipment used when mounting the second object relative to the first object, which is information corresponding to the mounting position deviation amount, in addition to the first information.

A program according to one aspect of the present disclosure is a program for causing one or more processors to execute the quality change detection method.

FIG. 1 is a schematic diagram of a substrate manufacturing line to which a quality change detection system according to an embodiment of the present invention is applied. FIG. 2 is a schematic plan view of a mounting system that is a detection target of the quality change detection system. FIG. 3 is a cross-sectional view taken along line AA of FIG. FIG. 4 is a block diagram of the above quality change detection system. FIG. 5 is a block diagram of an implementation system that is a detection target of the above quality change detection system. 6A and 6B are diagrams showing the distribution of mounting positions of a second object relative to a first object, generated by the quality change detection system of the same embodiment, and the distribution of mounting positions of a second object relative to a first object for each mounting angle of the second object relative to the first object, generated by the quality change detection system of the same embodiment. Figure 7 is a graph generated by the above-mentioned quality change detection system showing the amount of mounting position deviation of a second object relative to a first object, and is a graph showing a case in which a second object that is not mounted properly relative to the first object is included. FIG. 8 is an explanatory diagram for explaining the first detection process of the quality change detection system. 9A to 9C are graphs for explaining the second detection process of the above quality change detection system. FIG. 10 is a flowchart showing a quality change detection method executed by the above quality change detection system.

(Embodiment)
Hereinafter, a quality change detection method and a quality change detection system according to an embodiment will be described with reference to the drawings. However, the embodiment and modified examples described below are merely examples of the present disclosure, and the present disclosure is not limited to the following embodiment and modified examples. Even if the embodiment and modified examples are not described below, various modifications can be made according to the design, etc., as long as they do not deviate from the technical idea of the present disclosure.

In addition, all figures described in the following embodiments are schematic diagrams, and the ratios of size and thickness of each component in each figure do not necessarily reflect the actual dimensional ratios.

The mounted component inspection device (quality change detection system) described in Patent Document 1 can detect the occurrence of mounting defects of a component (second object) on a printed circuit board (first object), but cannot prevent the occurrence of mounting defects in advance.

(1) Overview First, an overview of a quality change detection method and a quality change detection system 1 according to the present embodiment will be described with reference to FIGS. 1 to 3. FIG.

The quality change detection method of this embodiment is a method for detecting a change in the quality of processing of a first object T1. The quality change detection system 1 of this embodiment is a system used in the above-mentioned quality change detection method. As shown in Figures 2 and 3, a second object T2 is mounted (processed) on a first object T1 by a mounting system 22. The mounting system 22 is a mounting device (mounting machine) used in the production of various products such as electronic devices, automobiles, clothing, food, medicines, and crafts in facilities such as factories, laboratories, offices, and educational facilities.

In this embodiment, a case will be described in which the mounting system 22 is used in the manufacture of electronic devices in a factory. Typical electronic devices have various circuit boards, such as a power supply circuit and a control circuit. In the manufacture of these circuit boards, as an example, a solder application process, a mounting process, and a reflow process are performed in this order. In the solder application process, cream solder is applied (or printed) to a board (including a printed wiring board). In the mounting process, components (including electronic components) are mounted (mounted) on the board. In the reflow process, for example, the board with the components mounted thereon is heated in a reflow furnace to melt the cream solder and perform soldering.

Three inspection processes (first to third inspection processes) are performed between the solder application process and the mounting process, between the mounting process and the reflow process, and after the reflow process. In the first inspection process, the application state of the cream solder on the board (position, size, film thickness, etc. of the cream solder on the board) is inspected. In the second inspection process, the mounting state of the second object T2 on the first object T1 before the reflow process is performed (mounting position, mounting angle, etc. of the second object T2 on the first object T1) is inspected. In the third inspection process, the mounting state of the second object T2 on the first object T1 after the reflow process is performed (mounting position, mounting angle, etc. of the second object T2 on the first object T1) is inspected.

These processes are carried out in the board manufacturing line 2 shown in Figure 1. The board manufacturing line 2 includes a printing system 21, a mounting system 22, a reflow system 23, a post-printing inspection system 24, a post-mounting inspection system 25, and a post-reflow inspection system 26.

In the solder application process, the printing system 21 (see FIG. 1) prints solder on the board 100 as the first object T1. In the mounting process, the mounting system 22 (see FIG. 1) mounts the component 200 as the second object T2 on the board 100 as the first object T1. The reflow system 23 heats the board 100 on which the component 200 is mounted via solder, melting the solder and soldering the component 200 to the board 100.

The post-printing inspection system 24 (see FIG. 1) inspects the printing state of the solder printed on the board 100, which is the first object T1, in a first inspection process. The post-mounting inspection system 25 (see FIG. 1) inspects the mounting state of the second object T2 on the first object T1 in a second inspection process. The post-reflow inspection system 26 (see FIG. 1) inspects the mounting state of the second object T2 on the first object T1 after reflow in a third inspection process.

Each piece of equipment that makes up the board production line 2 is connected to the quality change detection system 1 via a wired or wireless communication network, and data is sent and received between each piece of equipment and the quality change detection system 1. Here, the printing system 21, mounting system 22, reflow system 23, post-printing inspection system 24, post-mounting inspection system 25, and post-reflow inspection system 26 each refer in principle to a single device, but also include configurations in which the control unit or memory unit of the device is located outside the device, or configurations in which the functions of the device are realized by combining multiple modules. Also included is a configuration in which multiple devices of the same type are grouped together.

The quality change detection system 1 according to this embodiment detects a change in the quality of the first object T1 manufactured in the board manufacturing line 2 (see FIG. 1) based on the first information D1. The first information D1 is information acquired in the second inspection process, and is input from the post-mounting inspection system 25 described below.

That is, the quality change detection method according to the present embodiment is a method for detecting a change in the quality of mounting when the second object T2 is mounted on the first object T1 in the mounting process. The mounting quality control method includes an acquisition step and a first judgment step (steps ST1 to ST3 in FIG. 10). The acquisition step is a step of acquiring data on the component 200 to be detected from the mounting position deviation amount, which is the difference between the actual mounting position of the second object T2 relative to the first object T1 and the target mounting position, contained in the first information D1 from the post-mounting inspection system 25. The acquired data is grouped by component type or mounting angle, for example. The first judgment step is a step of judging that the quality of mounting has changed when the mounting position deviation amount acquired in the acquisition step exceeds the first judgment range R1 (see FIG. 7) and falls within the second judgment range R2 (see FIG. 7). The second judgment range R2 is a range in which the quality of mounting is judged to be normal.

The quality change detection system 1 according to this embodiment is a system used in the above-mentioned quality change detection method. As shown in FIG. 4, the quality change detection system 1 includes an acquisition unit 11 and a judgment unit 12. The acquisition unit 11 acquires a mounting position deviation amount, which is a difference between an actual mounting position and a target mounting position of the second object T2 with respect to the first object T1 that has undergone a mounting process in which the second object T2 is mounted on the first object T1. The judgment unit 12 judges that the quality of the mounting has changed when the mounting position deviation amount acquired by the acquisition unit 11 exceeds the first judgment range R1 (see FIG. 7) and falls within the second judgment range R2 (see FIG. 7). The second judgment range R2 is a range in which the quality of the mounting is judged to be normal.

In this disclosure, "normal mounting quality" means that the quality at least meets the range that is judged to be normal by the post-mounting inspection system 25 that outputs information to the quality change detection system 1.

In the quality change detection method and quality change detection system 1 according to this embodiment, even if the mounting position deviation amount is within the second judgment range R2 in which the mounting quality is judged to be normal, if it exceeds the first judgment range R1, it is judged that the mounting quality has changed. Therefore, it is possible to know that the mounting quality is changing in the direction of becoming abnormal (defective) before the mounting position deviation amount exceeds the second judgment range R2. This makes it possible to prevent the occurrence of mounting defects of the second object T2 relative to the first object T1.

(2) Details Next, the quality change detection method and quality change detection system 1 according to the present embodiment will be described in detail with reference to FIGS. 1 to 5. FIG.

(2.1) Premise In the present embodiment, as an example, a case will be described in which the mounting system 22 is used to mount a component (second object T2) by surface mount technology (SMT). That is, the component 200 as the second object T2 is a surface mount component (SMD: Surface Mount Device), and is mounted by being placed on the surface (mounting surface 101) of the substrate 100 as the first object T1. However, the present invention is not limited to this example, and the mounting system 22 may be used to mount a component (second object T2) by insertion mount technology (IMT). In this case, the component 200 as the second object T2 is a component for insertion mounting having lead terminals, and is mounted on the surface (mounting surface 101) of the substrate 100 as the first object T1 by inserting the lead terminals into holes in the substrate 100.

In other words, "mounting" in this disclosure includes placing a component 200 as a second object T2 on the mounting surface 101 of a substrate 100 as a first object T1, attaching the component 200 to the mounting surface 101 of the substrate 100, and inserting a lead terminal of the component 200 into a hole in the substrate 100. Also, "mounting" in this disclosure includes joining the component 200 to the substrate 100 and gluing the component 200 to the substrate 100.

In addition, "mounting quality" in this disclosure refers to the quality when mounting a component 200 as a second object T2 on a board 100 as a first object T1, and includes the mounting position and mounting angle of the component 200 with respect to the board 100. More specifically, "mounting quality" includes the mounting position in the first direction (X-axis direction) of the board 100, the mounting position in the second direction (Y-axis direction) of the board 100, and the mounting angle within the mounting surface 101 of the board 100.

In addition, in the present disclosure, "the quality of mounting changes" refers to a change in the direction away from the range in which the quality of mounting is judged to be normal (i.e., a change in the direction in which the quality of mounting is judged to be abnormal). For example, in this embodiment, this means a change in the mounting position (or mounting angle) of the second object T2 relative to the first object T1.

In addition, in this disclosure, "determining that the quality of mounting has changed" means determining whether the amount of deviation of the mounting position (or mounting angle) of the second object T2 relative to the first object T1 exceeds a first judgment range R1 (see Figure 5) included in a second judgment range R2 (see Figure 5) in which the quality of mounting is determined to be normal, or that the distribution of the amount of deviation of the mounting position (or mounting angle) of the second object T2 that falls within the first judgment range R1 changes.

In addition, the "target mounting position" in this disclosure refers to the position (coordinates) where the component 200, which is the second object T2, is to be mounted on the board 100, which is the first object T1. In this embodiment, as shown in Figure 2, the board 100 is placed parallel to the X-Y plane described below, so the target mounting position is expressed by the coordinate in the X-axis direction (X coordinate) and the coordinate in the Y-axis direction (Y coordinate).

In the following, as an example, three mutually orthogonal axes, the X-axis, the Y-axis, and the Z-axis, are set, and the axes parallel to the surface (mounting surface 101) of the substrate 100, which is the first object T1, are defined as the "X-axis" and "Y-axis", and the axis parallel to the thickness direction of the substrate 100 is defined as the "Z" axis. Furthermore, the side of the capture unit 2211 seen from the substrate 100, which is the first object T1, is defined as the positive direction of the Z-axis (also referred to as "above"). In addition, the state seen from the positive direction of the Z-axis (above) is also referred to as "planar view" below. The X-axis, Y-axis, and Z-axis are all virtual axes, and the arrows indicating "X", "Y", and "Z" in the drawings are merely indicated for the purpose of explanation, and none of them have any substance. Furthermore, these directions are not intended to limit the directions in which the mounting system 22 is used.

In addition, pipes for circulating cooling water, cables for supplying power, and pipes for supplying air pressure (including positive pressure and vacuum) are connected to the mounting system 22, but in this embodiment, these are omitted from the illustration as appropriate.

(2.2) Quality Change Detection System Next, the configuration of the quality change detection system 1 according to this embodiment will be described with reference to FIG.

In this embodiment, the quality change detection system 1 is mainly configured as a computer system having one or more processors and one or more memories. That is, the functions of the quality change detection system 1 are realized by one or more processors executing a program recorded in one or more memories of the computer system. The program may be pre-recorded in the memory, may be provided via a telecommunications line such as the Internet, or may be recorded on a non-transitory recording medium such as a memory card and provided.

As shown in Fig. 4, the quality change detection system 1 according to this embodiment includes an acquisition unit 11 and a determination unit 12. In addition to the acquisition unit 11 and the determination unit 12, the quality change detection system 1 according to this embodiment further includes a prediction unit 13, a factor estimation unit 14, a creation unit 15, and a notification unit 16.

In this embodiment, as described above, the quality change detection system 1 mainly comprises a computer system having one or more processors and one or more memories. Therefore, each component of the quality change detection system 1 (acquisition unit 11, judgment unit 12, prediction unit 13, factor estimation unit 14, creation unit 15, and notification unit 16) is realized by one or more processors executing a program.

(2.2.1) Acquisition Unit As described above, the acquisition unit 11 acquires the mounting position deviation amount, which is the difference between the actual mounting position of the second object T2 relative to the first object T1 and the target mounting position. That is, the step (process) in which the acquisition unit 11 acquires the mounting position deviation amount is the acquisition step of the quality change detection method according to this embodiment. Specifically, the acquisition unit 11 acquires the first information D1 from a post-mounting inspection system 25 (see FIG. 1) described later. The acquisition unit 11 may also acquire the second information D2 from a mounting system 22 described later. In this embodiment, the acquisition unit 11 acquires the first information D1 at the timing when the inspection of one board 100 as the first object T1 is completed in the post-mounting inspection system 25. The acquisition unit 11 may also acquire the first information D1 at the timing when the inspection of a required number of boards 100 is completed for distribution change detection F2 (see FIG. 10) described later. In this embodiment, the acquisition unit 11 acquires the first information D1 for all the second objects T2 mounted on the mounting surface 101 of one board 100. The acquisition unit 11 outputs the acquired first information D1 to the determination unit 12 for each type of component 200.

Here, the "type of component" includes the type of element (resistor, capacitor, lead component, etc.) and the size of the component (0402, 0603, 1005, etc., not limited to actual dimensions, including dimensions according to standards and data). In addition, "by type of component" includes at least the meaning of by type of element, by size of component, and by type of element and by size of component. For example, the first information D1 of a resistor of 0603 size and the first information D1 of a resistor of 1005 size are output separately to the judgment unit 12. That is, even if the type of element is the same, if the size of the component is different, they are output separately to the judgment unit 12. Furthermore, the first information D1 may be output to the judgment unit 12 for each type of component and for each mounting angle. In this embodiment, the acquisition unit 11 acquires the first information D1 from the management computer 3 (see FIG. 4) that manages information on the devices that make up the board manufacturing line 2.

The first information D1 includes a mounting position deviation amount, which is the difference between the actual mounting position of the second object T2 relative to the first object T1 and the target mounting position of the second object T2 relative to the first object T1. The first information D1 may further include a mounting angle deviation amount, which is the difference between the actual mounting angle of the second object T2 relative to the first object T1 and the target mounting angle of the second object T2 relative to the first object T1. In this embodiment, it is described that only the mounting position deviation amount is included in the first information D1. The mounting position deviation amount includes a first mounting position deviation amount, which is the deviation amount in the X-axis direction, and a second mounting position deviation amount, which is the deviation amount in the Y-axis direction. The first information D1 includes the mounting position deviation amount before the reflow process is performed.

The second information D2 is information acquired from at least one of the equipments constituting the board manufacturing line 2. In this embodiment, the second information D2 is information acquired from the mounting system 22, which is one of the equipments 4 among the multiple equipments (see FIG. 4). The second information D2 includes lot information, trace information, event information, and production information (production data). The lot information is information about the type of board 100 on which the component 200 corresponding to the above-mentioned first information D1 is mounted, and includes, for example, information about the production lot for each board 100 and the production date and time of the board 100. The trace information includes information about the address of the nozzle 2211 and feeder (i.e., the nozzle holder at which the nozzle 2211 was mounted and the feeder at which the nozzle was supplied) used when mounting the component 200 corresponding to the above-mentioned first information D1, information acquired by a sensor (e.g., the component recognition camera 222) provided in the mounting system 22, and a correction amount (e.g., a recognition correction amount) based on the information acquired by the sensor. The event information is information about an event performed in the mounting process by the mounting system 22, and includes, for example, the replacement of a feeder. The production information includes, for example, a target mounting position of the component 200 on the board 100, a target mounting angle, a circuit number, and a component code for individually identifying the component 200. The component code includes information such as the size of the component, the type of element (i.e., resistor or capacitor), and the vendor of the component.

(2.2.2) Determination Unit The determination unit 12 determines that the quality of the mounting has changed based on the first information D1 from the acquisition unit 11. More specifically, the determination unit 12 determines that the quality of the mounting has changed when the amount of mounting position deviation from the acquisition unit 11 exceeds the first determination range R1 (see FIG. 7) and falls within the second determination range R2 (see FIG. 7) in which the quality of the mounting is determined to be normal. The determination unit 12 also determines that the quality of the mounting has changed based on statistical information regarding the amount of mounting position deviation included in the first determination range R1. That is, the step (process) in which the determination unit 12 determines that the quality of the mounting has changed is the determination step (first determination step and second determination step) of the quality change detection method according to this embodiment.

The quality change detection method according to this embodiment has a first judgment step and a second judgment step as judgment steps. The first judgment step is a step of judging that the quality of the mounting has changed when the mounting position deviation amount exceeds the first judgment range R1 and falls within the second judgment range R2. The second judgment step is a step of judging that the quality of the mounting has changed based on statistical information regarding the mounting position deviation amount of the second object T2 included in the first judgment range R1. The first judgment range R1 is set based on the standard deviation of the normal state distribution (see FIG. 9A) created by the creation unit 15 described later. In other words, the normal state distribution (see FIG. 9A) is a distribution that indicates how the mounting position deviation amount of the second object T2 fluctuates if the state of the board manufacturing line 2 is normal.

Figure 6A is a diagram showing the distribution of mounting positions of the second object T2 relative to the first object T1 by type of component and by production lot. In this embodiment, by type of component means by size of component and type of element. Figure 6A shows the distribution of mounting positions of the second object T2 in the X-axis direction. The graphs lined up in the horizontal axis direction in Figure 6A (two in the illustrated example) show graphs of different production lots, and the graphs lined up in the vertical axis direction in Figure 6A (two in the illustrated example) show graphs of different types of components. In addition, the vertical axis in each graph shows the amount of mounting position deviation, and the horizontal axis in each graph shows the number of times each mounting position deviation is mounted, i.e., the number of occurrences.

With reference to the two graphs in FIG. 6A, which are arranged in the horizontal direction and show the same type of parts but different production lots, it can be seen that even if the production lots are different, if the type of parts is the same (i.e., if the type of second object T2 is the same), the change in the distribution of the mounting positions of the second object T2 is small (the shape of the distribution can be considered to be equivalent). On the other hand, with reference to the graphs in FIG. 6A, which are arranged in the vertical direction and show the same production lot but different types of parts, it can be seen that even if the production lots are the same, if the types of parts are different (i.e., if the type of second object T2 is different), the change in the distribution of the mounting positions of the second object T2 is large (the shape of the distribution cannot be considered to be equivalent). In short, the distribution of the mounting positions of the second object T2 varies more greatly depending on the type of the second object T2 (part 200) than on the production lot. Therefore, it is preferable that the normal state distribution is set according to the type of part 200, which is the second object T2. Here, it is preferable that the first judgment range R1 (see FIG. 8) is set according to the type of the second object T2. Similarly, the second determination range R2 (see FIG. 8) is also preferably set according to the type of the second object T2.

The distribution of the mounting position deviation amount of the second object T2 in the Y-axis direction also varies more greatly depending on the type of part than on the production lot (the shape of the distribution cannot be considered equivalent). Therefore, only the distribution of the mounting position in the X-axis direction will be described here, and the distribution of the mounting position deviation amount in the Y-axis direction will be omitted.

Figure 6B is a diagram showing the distribution of mounting positions of the second object T2 relative to the first object T1 for each mounting angle of the second object T2 relative to the first object T1. Like Figure 6A, Figure 6B shows the distribution of mounting positions of the second object T2 in the X-axis direction. The vertical axis in each graph indicates the amount of mounting position deviation, and the horizontal axis in each graph indicates the number of occurrences.

Furthermore, the graph on the left side of FIG. 6B shows the case where the mounting angle of the second object T2 relative to the first object T1 is 90 degrees, and the graph on the right side of FIG. 6B shows the case where the mounting angle is 0 degrees. Comparing the graph when the mounting angle is 90 degrees with the graph when the mounting angle is 0 degrees, it can be seen that the distribution of the mounting position deviation amount of the second object T2 is different. In short, the distribution of the mounting position deviation amount of the second object T2 changes significantly depending on the mounting angle of the second object T2 relative to the first object T1 (the shape of the distribution cannot be considered to be equivalent). Therefore, it is preferable that the normal state distribution is set according to the mounting angle of the component 200, which is the second object T2, relative to the first object T1. Here, it is preferable that the first judgment range R1 (see FIG. 8) is set according to the mounting angle of the component 200, which is the second object T2, relative to the first object T1. Similarly, the second determination range R2 is also preferably set according to the mounting angle of the component 200, which is the second object T2, relative to the first object T1.

(2.2.2.1) First Judgment Step (Outlier Detection F1)
The first judgment range R1 is a range defined by a first threshold value TH11 and a second threshold value TH12, as shown in Fig. 7. Here, in this embodiment, the absolute values of the first threshold value TH11 and the second threshold value TH12 are different, but the absolute values of the first threshold value TH11 and the second threshold value TH12 may be the same. In Fig. 7, the horizontal axis indicates the elapsed time t, and the vertical axis indicates the mounting position deviation amount GapX of the second object T2.

As described above, the second judgment range R2 is a range in which the quality of mounting is judged to be normal. As shown in FIG. 7, the second judgment range R2 is a range defined by the first threshold TH21 and the second threshold TH22. Here, in this embodiment, the absolute values of the first threshold TH21 and the second threshold TH22 are different, but the absolute values of the first threshold TH21 and the second threshold TH22 may be the same. Also, in FIG. 7, the "circle" that exceeds the first threshold TH11 indicates an outlier of the mounting position deviation amount GapX of the second object T2. The "outlier" here refers to a value that falls within the second judgment range R2 but exceeds the first judgment range R1 (see "Ou1" and "Ou2" in FIG. 8). Note that "DI1" in FIG. 8 indicates the distribution of the mounting position deviation amount GapX of the second object T2 (hereinafter referred to as "distribution DI1").

Therefore, as described above, the judgment unit 12 judges that the quality of mounting has changed when the mounting position deviation amount GapX (outliers Ou1 and Ou2 in FIG. 8) exceeds the first judgment range R1 and falls within the second judgment range R2. That is, in this embodiment, as shown in FIG. 7 and FIG. 8, the first judgment range R1 is included in the second judgment range R2.

The first judgment range R1 is set according to the type of the second object T2, as described above. When the type of the second object T2 is different, the judgment unit 12 judges that the quality of the mounting of the second object T2 has changed based on the first judgment range R1 set according to the type of the second object T2. Also, the first judgment range R1 is set according to the mounting angle of the second object T2 relative to the first object T1, as described above. When the mounting angle of the second object T2 relative to the first object T1 is different, the judgment unit 12 judges that the quality of the mounting has changed based on the first judgment range R1 set according to the mounting angle. Note that the judgment unit 12 may also judge that the quality of the mounting has changed based on the first judgment range R1 set according to the feeder (feeder serial number or address) used to mount the second object T2. That is, the determination unit 12 determines that the mounting quality has changed based on the determination criteria generated for each different category (the type of the second object T2, the mounting angle, the feeder used for supply, etc.) This clarifies the deviation from the determination criteria for a specific category, and makes the change in mounting quality apparent.

(2.2.2.2) Second Judgment Step (Distribution Change Detection F2)
Furthermore, when a certain number or more of the second objects T2 whose mounting position misalignment amounts are included in the first judgment range R1 are collected among the multiple second objects T2 mounted on the mounting surface 101 of the board 100 as the first object T1, the judgment unit 12 executes distribution change detection F2 (see FIG. 10 ) described below. That is, the judgment unit 12 judges that the mounting quality has changed based on statistical information regarding the mounting position misalignment amounts of the second objects T2 included in the first judgment range R1.

The statistical information includes at least one of an average calculated based on the distribution of the mounting position deviation amount of the second object T2 and a variance (or standard deviation) calculated based on the distribution of the mounting position deviation amount of the second object T2. In this embodiment, the statistical information includes both an average calculated from the distribution of the mounting position deviation amount of the second object T2 and a variance (or standard deviation) calculated from the distribution of the mounting position deviation amount of the second object T2. For example, as shown in FIG. 9B, when the difference between the average calculated from the distribution DI1 of the mounting position deviation amount of the second object T2 and the average calculated from the normal state distribution is large (above the threshold value of step ST7 in FIG. 10), the determination unit 12 determines that the quality of the mounting has changed. In addition, for example, as shown in FIG. 9C, when the ratio of the variance calculated from the distribution DI1 of the mounting position deviation amount of the second object T2 to the variance calculated from the normal state distribution is large (i.e., the distribution DI1 is wider than the normal state distribution), the determination unit 12 determines that the quality of the mounting has changed.

Note that Figure 9A is a diagram showing the normal state distribution obtained from past first information D1. In Figure 9A, the distribution DI1 of the mounting position deviation amount of the second object T2 is distributed with the mounting position deviation amount near zero as the average. Also, the scale on the left side in Figures 9A to 9C (value of the number of occurrences) is the scale for the normal state distribution, and the distribution DI1 of the mounting position deviation amount of the second object T2 in Figures 9B and 9C has been normalized to match the normal state distribution.

(2.2.3) Prediction Unit The prediction unit 13 predicts an abnormality (failure) in the mounting quality based on the judgment result of the judgment unit 12. Here, the abnormality in the mounting quality occurs when the mounting position deviation amount of a specific second object T2, of the multiple second objects T2 mounted on the first object T1, whose mounting position deviation amount exceeds the first judgment range R1, exceeds the second judgment range R2. In other words, before the abnormality in the mounting quality, the mounting quality changes. Therefore, the prediction unit 13 predicts the abnormality in the mounting quality based on the first information D1 from the post-mounting inspection system 25. That is, the step (process) in which the prediction unit 13 predicts the abnormality in the mounting quality is the prediction step. For example, when the judgment unit 12 judges that the mounting position deviation amount of the second object T2 has changed in a direction exceeding the second judgment range R2, the prediction unit 13 predicts that the mounting quality will become abnormal (failure).

In addition, in the prediction step, the prediction unit 13 predicts at least the time until an abnormality occurs in the board manufacturing line 2. Specifically, the prediction unit 13 stores, for example, the time until the mounting position deviation amount of the second object T2 becomes an outlier Ou1 (or Ou2) that exceeds the first judgment range R1 from an initial position that falls within the first judgment range R1 (exceeding the first judgment range R1 in FIG. 7), and predicts the time until the outliers Ou1 and Ou2 exceed the second judgment range R2 based on this time. In this way, according to the quality change detection method and quality change detection system 1 of this embodiment, it is possible to predict the time until an abnormality occurs in the mounting quality.

The prediction unit 13 may predict the probability of an abnormality occurring in the quality of mounting after a predetermined time has elapsed, the number of abnormalities occurring, etc. Alternatively, the prediction unit 13 may predict the probability of an abnormality occurring per production volume or per production lot, the number of abnormalities occurring, etc.

(2.2.4) Factor Estimation Unit The factor estimation unit 14 estimates the malfunction location in the board manufacturing line 2 that is the cause of the change in mounting quality based on the information on the mounting position deviation amount. The estimation step is a step (process) in which the factor estimation unit 14 estimates the malfunction location in the board manufacturing line 2 that is the cause of the change in mounting quality. For example, when the determination unit 12 determines that the mounting position deviation amount of the second object T2 has changed in a direction exceeding the first determination range R1, information on the fluctuation of the correction amount (recognition correction amount) of the mounting position of the specific second object T2 calculated based on the image capture result by the component recognition camera 222 described later is called from the second information D2 from the mounting system 22. If there is a correlation between the change in the mounting position deviation amount in a direction exceeding the first determination range R1 and the fluctuation of the recognition correction amount, it is estimated that the change in mounting quality is caused by a malfunction in the suction process. Alternatively, if the change in the mounting position deviation amount in a direction exceeding the first determination range R1 occurs when the second object T2 is supplied from a specific feeder, it is estimated that the change in mounting quality is caused by a malfunction of the specific feeder. That is, the cause estimation unit 14 estimates the malfunction location using, in addition to the first information D1 from the post-mounting inspection system 25, the second information D2 from the mounting system 22, which is information corresponding to the amount of mounting position deviation and is equipment 4 used when mounting the second object T2 on the first object T1.

The malfunctioning points estimated by the cause estimation unit 14 are not limited to units that constitute the equipment 4, such as feeders, heads, and nozzles, but also include processes such as the suction process and printing process, and the equipment 4 that constitutes the board manufacturing line 2.

In addition, the cause estimation unit 14 may estimate the downtime (time loss of operation) due to failure of the estimated malfunctioning part, such as a feeder, head, or nozzle, and the appropriate timing for maintenance of the malfunctioning part.

(2.2.5) Creation Unit The creation unit 15 creates a normal state distribution from the mounting position deviation amounts that have been judged to be normal in the past through a mounting process (i.e., within the second judgment range R2). The normal state distribution is created for each type of the second object T2 to be detected and each combination of mounting angles. For example, when a resistor of 0603 size and a resistor of 1005 size are detected, a normal state distribution is created from the mounting position deviation amounts corresponding to the resistor of 0603 size and the mounting position deviation amounts corresponding to the resistor of 1005 size. The first judgment range R1 is calculated from the standard deviation of the normal state distribution. When there is a normal state distribution corresponding to the second object T2 to be detected, information on the first judgment range R1, average, and variance calculated from the normal state distribution is output to the judgment unit 12. It is preferable that the number of data on the mounting position deviation amounts is large in order to ensure the accuracy of the normal state distribution. Therefore, data on the mounting position deviation amounts is collected across multiple production lots. As an example, the number of data on the mounting position deviation amounts is 8000 points on average. The normal state distribution may be updated when a sufficient amount of data on the amount of mounting position misalignment is collected. For example, the normal state distribution may be updated at a predetermined interval when a certain amount of data on the amount of mounting position misalignment for each type of component is accumulated, for example, once a day, and the update timing may be set appropriately.

(2.2.6) Notification Unit The notification unit 16 notifies, for example, a manager (worker) of a factory of at least one of the judgment result of the judgment unit 12 and the prediction result of the prediction unit 13. In this embodiment, the notification unit 16 notifies the worker of the judgment result in the first judgment step of the judgment unit 12, the judgment result in the second judgment step of the judgment unit 12, and the prediction result of the prediction unit 13. For example, when the judgment unit 12 judges that the mounting position deviation amount is approaching the threshold value (TH11, TH12) of the first judgment range R1, the notification unit 16 notifies the worker that the mounting quality has changed, and when the judgment unit 12 judges that the mounting position deviation amount cannot be regarded as equivalent to the normal state distribution based on the statistical information (average and variance) calculated from the distribution of the mounting position deviation amount included in the first judgment range R1, the notification unit 16 notifies the worker that the mounting quality has changed. In addition, when the prediction unit 13 predicts that the quality of mounting will become abnormal (defective), the notification unit 16 notifies the worker that an abnormality (defect) in the quality of mounting will occur. Here, the manner of notification performed by the notification unit 16 includes, for example, displaying or lighting on the display unit (liquid crystal display or light-emitting unit) of the equipment 4, transmitting data to a terminal (personal computer, tablet, smartphone, etc.) used by the worker, displaying, outputting audio, recording (writing) to a non-transitory recording medium, and printing (printing out), etc. Note that the notification unit 16 may notify any one of the judgment results in the first judgment step and the judgment results in the second judgment step of the judgment unit 12, and the prediction result of the prediction unit 13.

(2.3) Mounting System Next, the configuration of the mounting system 22 according to this embodiment will be described with reference to FIGS. 2, 3, and 5. FIG.

As shown in Figures 2, 3 and 5, the mounting system 22 in this embodiment includes a mounting head 221, a component recognition camera 222, a control device 223, a driving device 224, a component supply device 225, and a conveying device 226.

(2.3.1) Mounting Head The mounting head 221 has at least one capture portion 2211. In this embodiment, the mounting head 221 has a plurality of capture portions 2211. The mounting head 221 moves the capture portion 2211 so as to approach the first object T1 (substrate 100) in a state in which the second object T2 (component 200) is captured by the capture portion 2211, and mounts the second object T2 on the mounting surface 101 of the first object T1. In other words, the mounting head 221 holds the capture portion 2211 movably between a first position where the capture portion 2211 is closer to the first object T1 and a second position farther away from the first object T1 than the first position. In other words, the mounting head 221 holds the capture portion 2211 movably toward the first object T1.

In this embodiment, in addition to the capture portion 2211, the mounting head 221 further has an actuator 2212 (see FIG. 5) for moving the capture portion 2211, and a head body 2213 (see FIG. 3) that holds the capture portion 2211 and the actuator 2212. In the mounting system 22 according to this embodiment, one head body 2213 holds multiple capture portions 2211 and actuators 2212. This allows the mounting head 221 to capture multiple second objects T2 (components 200).

The capture unit 2211 is, for example, a suction nozzle. The capture unit 2211 is controlled by the control device 223 and can be switched between a capture state in which the second object T2 is captured (held) and a release state in which the second object T2 is released (released from capture). However, the capture unit 2211 is not limited to a suction nozzle that adsorbs the second object T2 by vacuum force, and may be configured to capture (hold) the second object T2 by, for example, a chuck mechanism or robot hand having a structure that physically clamps (pinch) the second object T2, or other configurations that adsorb (suck) the second object T2 by magnetic force or static electricity.

Regarding the capture of the second target T2 by the capture unit 2211, the mounting head 221 operates by receiving air pressure (vacuum) as a power source. In other words, the mounting head 221 switches the capture unit 2211 between a captured state and a released state by opening and closing a valve on the air pressure (vacuum) supply path connected to the capture unit 2211.

The actuator 2212 moves the capture portion 2211 linearly in the Z-axis direction. Furthermore, the actuator 2212 rotates the capture portion 2211 in a rotational direction (hereinafter referred to as the "θ direction") around an axis line along the Z-axis direction. In this embodiment, as an example, the actuator 2212 drives the capture portion 2211 in the Z-axis direction by a driving force generated by a linear motor. The actuator 2212 drives the capture portion 2211 in the θ direction by a driving force generated by a rotary motor. On the other hand, as described later, the mounting head 221 moves linearly in the X-axis direction and the Y-axis direction by the driving device 224. As a result, the capture portion 2211 included in the mounting head 221 can be moved in the X-axis direction, the Y-axis direction, the Z-axis direction, and the θ direction by the driving device 224 and the actuator 2212.

As an example, the head body 2213 is made of metal and formed into a rectangular parallelepiped shape. The capture portion 2211 and the actuator 2212 are assembled to the head body 2213, whereby the head body 2213 holds the capture portion 2211 and the actuator 2212. In this embodiment, the capture portion 2211 is indirectly held by the head body 2213 via the actuator 2212 in a state in which it can move in the Z-axis direction and the θ direction. The mounting head 221 moves within the X-Y plane as the head body 2213 is moved within the X-Y plane by the drive device 224.

According to the above-mentioned configuration, the mounting head 221, with the capturing portion 2211 capturing the second object T2 (component 200), moves the capturing portion 2211 so as to approach the first object T1 (substrate 100), and the second object T2 can be mounted on the mounting surface 101 of the first object T1. That is, the mounting head 221 moves the capturing portion 2211 at least between a first position that is closer to the first object T1 and a second position that is farther away from the first object T1 than the first position. In short, the mounting head 221 moves the capturing portion 2211, with the second object T2 captured, from the second position to the first position, thereby mounting the second object T2 on the mounting surface 101 of the first object T1.

In this embodiment, the mounting head 221 further has a head camera 2214 in addition to the capture unit 2211, the actuator 2212, and the head body 2213. The head camera 2214 is fixed to the mounting head 221 by being fixed to the side of the head body 2213. In this embodiment, the mounting system 22 has one head camera 2214. The head camera 2214 is, for example, an area camera. In this embodiment, the head camera 2214 is arranged with its imaging field of view facing downward, and images a board mark for positioning attached to the first object T1. The head camera 2214 may also image a specific area of the mounting surface 101 of the first object T1 (board 100) that includes a joining material (for example, solder).

(2.3.2) Component Recognition Camera The component recognition camera 222 is disposed on the base 220 of the mounting system 22 with its imaging field of view facing upward. The component recognition camera 222 captures an image of the underside of the component 200 held by the capture section 2211 of the mounting head 221 from below. Based on the captured image, the control device 223 (described later) calculates the amount of positional deviation of the component 200 relative to the capture section 2211 of the mounting head 221, and corrects the mounting position of the component 200 on the board 100 by the mounting head 221 based on the calculated amount of positional deviation. In this embodiment, the component recognition camera 222 is disposed on the base 220 of the mounting system 22, but is not limited thereto, and may be provided integrally with the mounting head 221, for example.

(2.3.3) Control Device The control device 223 controls each part of the mounting system 22. The control device 223 is mainly configured as a computer system having one or more processors and one or more memories. That is, the functions of the control device 223 are realized by one or more processors executing a program recorded in one or more memories of the computer system. The program may be recorded in the memory in advance, may be provided via a telecommunication line such as the Internet, or may be provided by recording it on a non-transitory recording medium such as a memory card.

The control device 223 is electrically connected to, for example, each of the mounting head 221, the head camera 2214, the component recognition camera 222, the drive device 224, the component supply device 225, and the transport device 226. The control device 223 outputs a control signal to the mounting head 221 and the drive device 224, and controls the mounting head 221 and the drive device 224 so that at least the second object T2 captured by the capture unit 2211 is mounted on the mounting surface 101 of the first object T1. The control device 223 also outputs a control signal to the head camera 2214 and the component recognition camera 222, controls the head camera 2214 and the component recognition camera 222, and acquires images captured by the head camera 2214 and the component recognition camera 222 from the head camera 2214 and the component recognition camera 222.

(2.3.4) Driving Device The driving device 224 is a device that moves the mounting head 221. In this embodiment, the driving device 224 moves the mounting head 221 within the XY plane. The "XY plane" here is a plane that includes the X-axis and the Y-axis and is perpendicular to the Z-axis. In other words, the driving device 224 moves the mounting head 221 in the X-axis direction and the Y-axis direction. In this embodiment, since the head camera 2214 is fixed to the mounting head 221, the driving device 224 also moves the head camera 2214 together with the mounting head 221. In other words, the driving device 224 moves the mounting head 221 and the head camera 2214 within the XY plane.

2 and 3, the drive device 224 has an X-axis drive unit 2241 and a Y-axis drive unit 2242. The X-axis drive unit 2241 moves the mounting head 221 linearly in the X-axis direction. The Y-axis drive unit 2242 moves the mounting head 221 linearly in the Y-axis direction. The Y-axis drive unit 2242 moves the mounting head 221 linearly in the Y-axis direction by moving the mounting head 221 together with the X-axis drive unit 2241 along the Y-axis. In this embodiment, as an example, each of the X-axis drive unit 2241 and the Y-axis drive unit 2242 includes a linear motor, and moves the mounting head 221 by a driving force generated by the linear motor upon receiving power supply.

(2.3.5) Component Supply Device The component supply device 225 supplies components 200 as second objects T2 to be captured by the capturing unit 2211 of the mounting head 221. As an example, the component supply device 225 has a plurality of tape feeders 2251 that supply the components 200 accommodated in the carrier tape 6. Alternatively, the component supply device 225 may have a tray on which a plurality of components 200 are placed. The mounting head 221 captures the second objects T2 (components 200) from such a component supply device 225 by the capturing unit 2211.

(2.3.6) Conveying Device The conveying device 226 is a device that conveys the substrate 100 as the first object T1. The conveying device 226 is realized, for example, by a belt conveyor or the like. The conveying device 226 conveys the first object T1 (substrate 100), for example, along the X-axis. The conveying device 226 conveys the first object T1 at least below the mounting head 221, that is, to a mounting space facing the capture unit 2211 in the Z-axis direction. Then, the conveying device 226 stops the first object T1 in the mounting space until the mounting head 221 completes mounting the second object T2 (component 200) on the first object T1 (substrate 100).

(2.3.7) Others In addition to the above configuration, the mounting system 22 includes, for example, a communication unit. The communication unit is configured to communicate with a higher-level system directly or indirectly via a network or a repeater. This allows the mounting system 22 to transmit and receive data to and from the higher-level system.

(2.4) Inspection System Next, the post-mounting inspection system 25 will be described.

As described above, the post-mounting inspection system 25 is a system for inspecting the mounting state of the second object T2 relative to the first object T1 in the second inspection process between the mounting process and the reflow process. As shown in FIG. 4, the post-mounting inspection system 25 is connected to the quality change detection system 1 via the management computer 3, and outputs first information D1 to the quality change detection system 1. As described above, the first information D1 includes the amount of mounting position deviation of the second object T2 relative to the first object T1 before the reflow process.

The post-mounting inspection system 25 calculates the amount of mounting position deviation of all second objects T2 mounted on the first object T1. Specifically, the post-mounting inspection system 25 calculates the difference between the actual mounting position of the second object T2 relative to the first object T1 and the target mounting position of the second object T2 relative to the first object T1 as the amount of mounting position deviation.

(3) Operation Next, the quality change detection method according to the present embodiment will be described with reference to FIG.

The acquisition unit 11 acquires the first information D1 from the post-mounting inspection system 25 and the second information D2 from the mounting system 22 at the timing when the production of a preset number of boards 100 (first objects T1) is completed. The acquisition unit 11 then groups (sorts) the first information D1 acquired from the post-mounting inspection system 25 by type of second object T2 and by mounting angle of the second object T2 relative to the first object T1, and outputs the grouped information to the determination unit 12. Here, the "timing when production is completed" may be the timing when all processes of production of the board 100 in the board manufacturing line 2 are completed, or the timing when inspection by the post-mounting inspection system 25 is completed.

When the first information D1 is input from the acquisition unit 11, the determination unit 12 executes outlier detection F1 (steps ST1 to ST3). In outlier detection F1, the determination unit 12 compares the absolute value of the mounting position deviation amount GapX of each second object T2 mounted on the first object T1 with the comparison value 3σ (step ST1). Here, "σ" in the comparison value 3σ is the standard deviation of the normal state distribution described above, and the comparison value 3σ is a value that defines the first judgment range R1. That is, the first judgment range R1 is a range defined by the comparison value +3σ and the comparison value -3σ. The comparison value is set for each category, and in this embodiment, the determination unit 12 makes a judgment based on the comparison value set for each type of component 200 and each mounting angle. If the absolute value of the mounting position deviation amount GapX is smaller than the comparison value 3σ (step ST1: Yes), the determination unit 12 temporarily stores the data of the mounting position deviation amount GapX in the buffer memory (step ST2). On the other hand, if the absolute value of the mounting position shift amount GapX is 3σ or more (step ST1: No), the determination unit 12 records the determination result that the mounting position shift amount GapX is an outlier (step ST3). The determination unit 12 executes outlier detection F1 for all second objects T2 mounted on the first object T1 (steps ST1 to ST3).

The determination unit 12 compares the number of data of the mounting position deviation amount GapX stored in the buffer memory with a preset threshold value (minimum number of data for determination) (step ST4). If the number of data is equal to or greater than the threshold value (step ST4: Yes), the determination unit 12 executes distribution change detection F2 (steps ST5 to ST9). Specifically, in distribution change detection F2, the determination unit 12 determines whether the distribution of the mounting position deviation amount GapX stored in the buffer memory and the normal state distribution created in advance by the creation unit 15 are equal variances based on the variance calculated from the distribution (step ST5). The term "equal variances" here includes not only the case where the two variances are completely equal, but also the case where the ratio of the two variances is within a certain range. As described above, the normal state distribution is obtained from the past first information D1.

If the distribution of the mounting position deviation amount GapX and the normal state distribution are not equal in variance (step ST5: No), that is, if the variance of the distribution of the mounting position deviation amount GapX has changed in a direction that is larger than the normal state distribution, the determination unit 12 records the determination result that the mounting position deviation amount GapX of the second object T2 has changed in a direction that exceeds the first determination range R1 (step ST6). Furthermore, the determination unit 12 determines whether the average value of the distribution of the mounting position deviation amount GapX and the average value of the normal state distribution are equal in average (step ST7). Here, "equal average" includes not only the case where the average values of the two are completely equal, but also the case where the ratio of the average values of the two is within a certain range.

If the two average values are not equal (step ST7: No), the determination unit 12 records the determination result that the mounting position deviation amount GapX of the second object T2 has changed in a direction that exceeds the first determination range R1 (step ST8). On the other hand, if the two average values are equal (step ST7: Yes), the determination unit 12 determines that the mounting position deviation amount GapX of each second object T2 is within the normal range (i.e., a range that does not exceed the second determination range R2), and resets (deletes) the data of the mounting position deviation amount GapX stored in the buffer memory (step ST9).

On the other hand, if the number of data is less than the threshold (step ST4: No), and if data to be judged remains (step ST10: Yes), the judgment unit 12 executes the above-mentioned outlier detection F1 and distribution change detection F2. On the other hand, if no data to be judged remains (step ST10: No), the judgment unit 12 ends the series of processes. In this embodiment, the step in which the acquisition unit 11 acquires the first information D1 is the acquisition step, and the above-mentioned steps ST1 to ST9 are the judgment steps.

In this way, in the quality change detection method and quality change detection system 1 according to this embodiment, as described above, even if the mounting position deviation amount GapX of the second object T2 is within the second judgment range R2 in which the mounting quality is judged to be normal, if it exceeds the first judgment range R1 or if it has changed in a direction that exceeds the first judgment range R1, it is judged that the mounting quality has changed. Therefore, it is possible to know that the mounting quality has changed in a direction that will cause an abnormality before the mounting position deviation amount GapX exceeds the second judgment range R2. This makes it possible to prevent the occurrence of mounting defects of the second object T2 relative to the first object T1.

(4) Modifications The above-described embodiment is merely one of various embodiments of the present disclosure. The above-described embodiment can be modified in various ways depending on the design, etc., as long as the object of the present disclosure can be achieved. In addition, functions similar to the quality change detection method according to the above-described embodiment may be embodied in a quality change detection system 1, a (computer) program, or a non-transitory recording medium having a program recorded thereon, etc. A program according to one aspect is a program for causing one or more processors to execute the quality change detection method according to the above-described embodiment.

Below, we list some variations of the above-mentioned embodiment. The variations described below can be applied in appropriate combinations.

The quality change detection system 1 in the present disclosure includes a computer system. The computer system is mainly composed of a processor and a memory as hardware. The function of the quality change detection system 1 in the present disclosure is realized by the processor executing a program recorded in the memory of the computer system. The program may be pre-recorded in the memory of the computer system, provided through an electric communication line, or recorded and provided in a non-transitory recording medium such as a memory card, an optical disk, or a hard disk drive that can be read by the computer system. The processor of the computer system is composed of one or more electronic circuits including a semiconductor integrated circuit (IC) or a large-scale integrated circuit (LSI). The integrated circuits such as IC or LSI referred to here are called differently depending on the degree of integration, and include integrated circuits called system LSI, VLSI (Very Large Scale Integration), or ULSI (Ultra Large Scale Integration). Furthermore, a field-programmable gate array (FPGA) that is programmed after the manufacture of the LSI, or a logic device that can reconfigure the connection relationship inside the LSI or reconfigure the circuit partition inside the LSI, can also be adopted as a processor. The electronic circuits may be integrated in one chip or distributed among multiple chips. The chips may be integrated in one device or distributed among multiple devices. The computer system referred to here includes a microcontroller having one or more processors and one or more memories. Thus, the microcontroller is also composed of one or more electronic circuits including a semiconductor integrated circuit or a large-scale integrated circuit.

Furthermore, it is not a required configuration for quality change detection system 1 that multiple functions in quality change detection system 1 are concentrated in one housing. The components of quality change detection system 1 may be distributed across multiple housings. Furthermore, at least some of the functions of quality change detection system 1 may be realized by the cloud (cloud computing) or the like.

In the mounting process, one mounting system 22 may be used to mount the second object T2 on the first object T1, or multiple mounting systems 22 (22A, 22B in Figure 1) may be used.

In the above embodiment, the quality of mounting is the quality when mounting the second object T2 on the first object T1 and includes the mounting position (or mounting angle), but it may also be the quality when capturing the second object T2 from the component supply device 225. In other words, the quality of mounting may include the position of the suction nozzle 2211 with respect to the second object T2.

In the above-described embodiment, the quality change detection method and the quality change detection system 1 are used for mounting misalignment in the mounting process, but for example, the quality change detection method and the quality change detection system 1 may be used for application misalignment in the solder application process. In this case, the acquisition unit 11 acquires the amount of positional misalignment between the position of the solder applied (printed) on the first object T1 and the position of the land from the post-printing inspection system 24.

In addition, in the above embodiment, the equipment 4 is the mounting system 22, but the equipment 4 is not limited to the mounting system 22 and may be, for example, the printing system 21. In this case, the first judgment range R1 may be set according to the type of cream solder.

In addition, in the above-described embodiment, the notification unit 16 notifies the worker of both the judgment result of the judgment unit 12 and the prediction result of the prediction unit 13, but the notification unit 16 may, for example, notify the worker of only the judgment result of the judgment unit 12, or may notify the worker of only the prediction result of the prediction unit 13. Furthermore, the notification unit 16 may notify not only the worker, but also a robot that performs maintenance work on the board production line 2 including the equipment 4 on behalf of the worker.

In addition, in the above-described embodiment, as shown in FIG. 10, the comparison value of the mounting position shift amount GapX of the second object T2 is 3σ, but for example, the comparison value may be 2σ or 1σ.

In the above embodiment, the determination unit 12 performs the distribution change detection F2 when a certain number or more of the second objects T2 that are not outliers detected in the outlier detection F1 are collected, as shown in FIG. 10. The determination unit 12 may perform the distribution change detection F2 in either the case where no outlier is detected in the outlier detection F1 or the case where an outlier is detected. The determination unit 12 may determine that the quality of mounting has changed based on the statistical information regarding the mounting position deviation amount GapX of the second object T2 even when the mounting position deviation amount GapX of all the second objects T2 is included in the first judgment range R1. Even in this case, the determination unit 12 can determine that the mounting position deviation amount GapX of the second object T2 has changed in a direction exceeding the first judgment range R1 by not having equal variance or equal average.

In the above embodiment, the first judgment range R1 (a range based on the standard deviation of the normal state distribution) is set for each type of the second object T2 and for each mounting angle of the second object T2 relative to the first object T1, but is not limited to this. For example, when the first judgment range R1 is set for each type of the second object T2, the same first judgment range R1 may be applied even if the mounting angle of the second object T2 relative to the first object T1 is different. Also, when the first judgment range R1 is set for each mounting angle of the second object T2 relative to the first object T1, the same first judgment range R1 may be applied even if the type of the second object T2 is different. Also, the first judgment range R1 may be applied for each unit (feeder or nozzle) used to mount the second object T2.

In the above embodiment, as shown in FIG. 8, the center of the first judgment range R1 and the center of the second judgment range R2 coincide with each other, and the first judgment range R1 and the second judgment range R2 are concentric. In contrast, the first judgment range R1 may be included in the second judgment range R2, and the center of the first judgment range R1 and the center of the second judgment range R2 may be shifted. In the above embodiment, the shape of each of the first judgment range R1 and the second judgment range R2 is a circle, but the shape of each of the first judgment range R1 and the second judgment range R2 may be, for example, an ellipse or a polygon (for example, a rectangle). Furthermore, the shape of each of the first judgment range R1 and the second judgment range R2 may be the same or different. Also, as shown in FIG. 9A to FIG. 9C, the average of the first judgment range R1 is not necessarily zero in the mounting position deviation amount.

In the above embodiment, the first information D1 is information acquired in the second inspection process, but is not limited to this. The first information may be information acquired in the third inspection process, or may include both information acquired in the second inspection process and information acquired in the third inspection process.

(summary)
As described above, the quality change detection method according to the first aspect includes an acquisition step and a first determination step. The acquisition step is a step of acquiring a mounting position deviation amount, which is a difference between an actual mounting position of a second object (T2) relative to a first object (T1) and a target mounting position. The first determination step is a step of determining that the mounting quality has changed when the mounting position deviation amount acquired in the acquisition step exceeds a first determination range (R1) and falls within a second determination range (R2). The first determination range (R1) is included in the second determination range (R2) in which the mounting quality is determined to be normal.

According to this aspect, it is possible to prevent poor mounting of the second object (T2) relative to the first object (T1).

The quality change detection method according to the second aspect further includes a second determination step in the first aspect. The second determination step is a step of determining that the quality of the mounting has changed based on statistical information regarding the mounting position deviation amount included in the first determination range (R1).

According to this aspect, it is possible to prevent poor mounting of the second object (T2) relative to the first object (T1).

In the quality change detection method relating to the third aspect, in the second aspect, the statistical information includes at least one of an average calculated from the distribution of the mounting position deviation amounts and a variance calculated from the distribution of the mounting position deviation amounts.

In the quality change detection method relating to the fourth aspect, in the second or third aspect, when a certain number or more of second objects (T2) whose mounting position deviation amount is included in the first judgment range (R1) are collected, a second judgment step is executed.

According to this aspect, it is possible to prevent poor mounting of the second object (T2) relative to the first object (T1).

In the quality change detection method relating to the fifth aspect, in any one of the first to fourth aspects, the first judgment range (R1) is set according to the type of the second object (T2).

According to this aspect, the first judgment range (R1) can be set according to the type of the second object (T2).

In the quality change detection method relating to the sixth aspect, in any one of the first to fifth aspects, the first judgment range (R1) is set according to the mounting angle of the second object (T2) relative to the first object (T1).

According to this aspect, the first judgment range (R1) can be set according to the mounting angle of the second object (T2) relative to the first object (T1).

The mounting quality control method according to the seventh aspect is any one of the first to sixth aspects, and further includes a prediction step. The prediction step is a step of predicting an abnormality in the quality of the mounting based on first information (D1). The first information (D1) is information regarding the amount of mounting position deviation.

According to this aspect, it is possible to prevent poor mounting of the second object (T2) relative to the first object (T1).

In the quality change detection method relating to the eighth aspect, in the seventh aspect, the prediction step predicts the time until an abnormality in the quality of at least the above implementation occurs.

According to this aspect, it is possible to predict the time until an abnormality in the quality of the above-mentioned implementation occurs.

The quality change detection method according to the ninth aspect is the seventh or eighth aspect, further comprising a notification step. The notification step is a step of notifying at least one of a plurality of results including the judgment result of the first judgment step and the prediction result of the prediction step.

According to this aspect, at least one of multiple results can be notified.

The quality change detection method according to the tenth aspect is any one of the first to ninth aspects, and further includes an estimation step. The estimation step is a step of estimating a malfunction location in the mounting system (22) that is the cause of the change in mounting quality, based on the first information (D1) related to the amount of mounting position deviation.

According to this aspect, it is possible to estimate the malfunction location in the mounting system (22).

In the quality change detection method according to the eleventh aspect, in the tenth aspect, in the estimation step, in addition to the first information (D1), second information (D2) is used. The second information (D2) is information corresponding to the amount of mounting position deviation, and is information about the equipment (4) used when mounting the second object (T2) on the first object (T1).

According to this aspect, it is possible to prevent poor mounting of the second object (T2) relative to the first object (T1).

In the quality change detection method relating to the 12th aspect, in any one of the first to 11th aspects, the first object (T1) is a component (200) and the second object (T2) is a board (100) on which the component (200) is mounted.

According to this aspect, it is possible to prevent defective mounting of the component (200) onto the substrate (100).

The quality change detection system (1) according to the thirteenth aspect includes an acquisition unit (11) and a judgment unit (12). The acquisition unit (11) acquires a mounting position deviation amount, which is the difference between an actual mounting position of a second object (T2) relative to a first object (T1) and a target mounting position. The judgment unit (12) judges that the mounting quality has changed when the mounting position deviation amount acquired by the acquisition unit (11) exceeds a first judgment range (R1) and falls within a second judgment range (R2). The first judgment range (R1) is included in a second judgment range (R2) in which the mounting quality is judged to be normal.

According to this aspect, it is possible to prevent poor mounting of the second object (T2) relative to the first object (T1).

The program relating to the 14th aspect is a program for causing one or more processors to execute a quality change detection method of any one of the first to 12th aspects.

According to this aspect, it is possible to prevent poor mounting of the second object (T2) relative to the first object (T1).

The configurations relating to the second to twelfth aspects are not essential to the quality change detection method and may be omitted as appropriate.

1 Quality change detection system 4 Equipment 11 Acquisition unit 12 Determination unit 100 Board 200 Component D1 First information D2 Second information R1 First determination range R2 Second determination range T1 First object T2 Second object

Claims (15)

an acquiring step of acquiring a mounting position deviation amount which is a difference between an actual mounting position of a second object with respect to a first object and a target mounting position;
a first determination step of determining that a quality of mounting has changed when the mounting position deviation amount acquired in the acquisition step exceeds a first determination range and is within a second determination range,
the first determination range is included in the second determination range in which the mounting quality is determined to be normal ;
a second determination step of determining that the mounting quality has changed based on statistical information regarding the mounting position deviation amount included in the first determination range.
Quality change detection method. The statistical information is
an average calculated from the distribution of the mounting position deviation amounts;
and a variance calculated from the distribution of the mounting position deviation amount.
The quality change detection method according to claim 1 . When the number of the second objects whose mounting position deviation amount is within the first determination range reaches a certain number or more, the second determination step is executed.
The quality change detection method according to claim 1 or 2. an acquiring step of acquiring a mounting position deviation amount which is a difference between an actual mounting position of a second object with respect to a first object and a target mounting position;
a first determination step of determining that a quality of mounting has changed when the mounting position deviation amount acquired in the acquisition step exceeds a first determination range and is within a second determination range,
the first determination range is included in the second determination range in which the mounting quality is determined to be normal;
the first determination range is set according to a mounting angle of the second object relative to the first object.
Quality change detection method. an acquiring step of acquiring a mounting position deviation amount which is a difference between an actual mounting position of a second object with respect to a first object and a target mounting position;
a first determination step of determining that a quality of mounting has changed when the mounting position deviation amount acquired in the acquisition step exceeds a first determination range and is within a second determination range,
the first determination range is included in the second determination range in which the mounting quality is determined to be normal;
The method further includes a prediction step of predicting an abnormality in the mounting quality based on the first information on the mounting position deviation amount.
Quality change detection method. In the prediction step, a time until an abnormality in at least the mounting quality occurs is predicted.
The quality change detection method according to claim 5 . a notification step of notifying at least one of a plurality of results including the determination result of the first determination step and the prediction result of the prediction step,
The quality change detection method according to claim 5 or 6 . an acquiring step of acquiring a mounting position deviation amount which is a difference between an actual mounting position of a second object with respect to a first object and a target mounting position;
a first determination step of determining that a quality of mounting has changed when the mounting position deviation amount acquired in the acquisition step exceeds a first determination range and is within a second determination range,
the first determination range is included in the second determination range in which the mounting quality is determined to be normal;
The method further includes an estimation step of estimating a malfunction location in the mounting system that is a cause of the change in the mounting quality based on the first information on the mounting position deviation amount,
In the estimation step, in addition to the first information, second information is used, which is information corresponding to the mounting position deviation amount and is related to equipment used when mounting the second object on the first object.
Quality change detection method. The first determination range is set according to the type of the second object.
The quality change detection method according to any one of claims 1 to 8 . the first object is a part,
The second object is a substrate on which the component is mounted.
The quality change detection method according to any one of claims 1 to 9. an acquisition unit that acquires a mounting position deviation amount that is a difference between an actual mounting position of a second object relative to a first object and a target mounting position;
a determination unit that determines that a quality of mounting has changed when the mounting position deviation amount acquired by the acquisition unit exceeds a first determination range and falls within a second determination range,
the first determination range is included in the second determination range in which the mounting quality is determined to be normal;
a second determination unit that determines that the mounting quality has changed based on statistical information regarding the mounting position deviation amount included in the first determination range.
Quality change detection system. an acquisition unit that acquires a mounting position deviation amount that is a difference between an actual mounting position of a second object relative to a first object and a target mounting position;
a determination unit that determines that a quality of mounting has changed when the mounting position deviation amount acquired by the acquisition unit exceeds a first determination range and falls within a second determination range,
the first determination range is included in the second determination range in which the mounting quality is determined to be normal;
the first determination range is set according to a mounting angle of the second object relative to the first object.
Quality change detection system. an acquisition unit that acquires a mounting position deviation amount that is a difference between an actual mounting position of a second object relative to a first object and a target mounting position;
a determination unit that determines that a quality of mounting has changed when the mounting position deviation amount acquired by the acquisition unit exceeds a first determination range and falls within a second determination range,
the first determination range is included in the second determination range in which the mounting quality is determined to be normal ;
a prediction unit that predicts an abnormality in the quality of the mounting based on the first information on the amount of mounting position deviation,
Quality change detection system. an acquisition unit that acquires a mounting position deviation amount that is a difference between an actual mounting position of a second object relative to a first object and a target mounting position;
a determination unit that determines that a quality of mounting has changed when the mounting position deviation amount acquired by the acquisition unit exceeds a first determination range and falls within a second determination range,
the first determination range is included in the second determination range in which the mounting quality is determined to be normal;
an estimation unit that estimates a malfunction location in the mounting system that is a cause of the change in mounting quality based on the first information on the mounting position deviation amount,
the estimation unit uses, in addition to the first information, second information corresponding to the mounting position deviation amount and related to equipment used when mounting the second object on the first object;
Quality change detection system. A program for causing one or more processors to execute the quality change detection method according to any one of claims 1 to 10.

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